package com.yuanchuang.yp.mall.web.admin.common.config.shiro;

import org.apache.shiro.authc.AuthenticationException;
import org.apache.shiro.authz.AuthorizationException;
import org.apache.shiro.web.filter.authc.BasicHttpAuthenticationFilter;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.RequestMethod;

import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * class_name: JwtFilter
 * package: com.yuanchuang.yp.mall.web.admin.common.config.shiro
 * describe: TODO
 * @author: yuanyaun
 * creat_date: 2019/7/16
 * creat_time: 15:29
 **/
public class JwtFilter extends BasicHttpAuthenticationFilter {

    /**
     * 执行登录认证
     * @param request
     * @param response
     * @param mappedValue
     * @return
     */
    @Override
    protected boolean isAccessAllowed(ServletRequest request, ServletResponse response, Object mappedValue) {

        if (isLoginAttempt(request, response)) {
            try {
                executeLogin(request, response);
            } catch (Exception e) {
                if (e instanceof AuthorizationException) {
                    throw new AuthorizationException("访问资源权限不足！");
                } else {
                    //token 异常 认证失败
                    throw new AuthenticationException("token 异常 认证失败");
                }
            }
        }
        return true;
    }
    @Override
    protected boolean isLoginAttempt(ServletRequest request, ServletResponse response) {
        String loginUrl = getLoginUrl();
        HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        String q = httpServletRequest.getRequestURI();
        if (q.equalsIgnoreCase(loginUrl)) {
            return false;
        }
        String authzHeader = this.getAuthzHeader(request);
        return authzHeader != null;
    }

    /**
     * 执行token验证
     */
    @Override
    protected boolean executeLogin(ServletRequest request, ServletResponse response) throws Exception {
        HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        String token = httpServletRequest.getHeader("Authorization");

        JwtToken jwtToken = new JwtToken(token);
        // 提交给realm进行登入，如果错误他会抛出异常并被捕获
        getSubject(request, response).login(jwtToken);
        // 如果没有抛出异常则代表登入成功，返回true
        return true;
    }



    /**
     * 对跨域提供支持
     */
    @Override
    protected boolean preHandle(ServletRequest request, ServletResponse response) throws Exception {
        HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        HttpServletResponse httpServletResponse = (HttpServletResponse) response;
        httpServletResponse.setHeader("Access-control-Allow-Origin", httpServletRequest.getHeader("Origin"));
        httpServletResponse.setHeader("Access-Control-Allow-Methods", "GET,POST,OPTIONS,PUT,DELETE");
        httpServletResponse.setHeader("Access-Control-Allow-Headers", httpServletRequest.getHeader("Access-Control-Request-Headers"));
        // 跨域时会首先发送一个option请求，这里我们给option请求直接返回正常状态
        if (httpServletRequest.getMethod().equals(RequestMethod.OPTIONS.name())) {
            httpServletResponse.setStatus(HttpStatus.OK.value());
            return false;
        }
        return super.preHandle(request, response);
    }
}
